The present invention is related to a weft thread machine with needles, warp thread guides, and a weft thread magazine.
Magazines of this type can be provided with a pair of chains for forwarding the weft thread which, in the vicinity of the guides, moves with a vector having a substantial horizontal component. The machine further comprises weft thread insertors which, when the needles move downwardly, move the weft threads from the hook side to the outtake side so that at the upper dead point of the needles, the threads are located in a substantially enclosed space between the outtake side of the needle and the innermost of the warp thread guides.
A warp knitting machine of this type is known in the art (see for example U.S. Pat. No. 4,442,684). In this machine the weft threads are supplied by the forwarding chains at an angle of about 30.degree. to the horizontal, are timely separated by the weft thread insertors and brought to the outtake side of the needles where they are tied in by the next stitch building step.
Where extremely thick weft thread material is used and/or where the stroke of the needle is short, it has been found that weft thread errors occur. In particular errors result from the so called "rearward lay" in which the weft threads are captured by the needle head and tear or can even break off the hook of the needle.
It is further known (DE-OS No. 2,319,348) to provide a machine in which the weft threads are forwarded in the grooves of two forwarding wheels which provide them with a substantially vertical travel path in the vicinity of the needles and permits them to be dropped substantially perpendicularly into the weft thread insertors. Since the weft threads hang between the forwarding tooth wheels and can thus interfere with the free movement of the weft thread insertors, certain warp thread guides of the rearmost guide bar are provided with a pair of protrusions located above each other. The lower protrusion holds the next weft thread to be supplied for such a time outside the grasp of the weft thread insertors till these have reached their weft thread capture position. Then the weft thread is released through the forward swinging of the guide bar and taken up by the weft thread insertor. The second protrusion insures an unequivocal separation of the sequentially following weft threads.
It is the purpose of the present invention to provide a warp knitting machine of the foregoing type wherein the danger of weft thread errors is substantially reduced.